Telephone-exchange system.



B. B. CLEMENT. TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED JULY 14, 1906.

1 1 ()7, 147, Patented Aug. 11, 1914.

3 SHEETS-SHEET 1.

glwaytl'oc Witness 2 I B. B. CLEMENT. TELEPHONE EXGHANGE SYSTEM.

APPLIGkTION FILED JULY 14, 1906.

Patented Aug. 11, 1914..

3 SHEETS-SHEET 2.

B. E. CLEMENT. TELEPHONE EXCHANGE SYSTEM.

AITPLIOKIION FILED JULY 14, 1906. v 1 107 147. I Patented Aug. 11, 1914.

3 SHEETS-SHEET 3.

Summntoz Witnesses EDWARD E. CLEMENT, or WASHINGTON, MESNE ASSIGNMENTS, T0 FREDERICK D S R T .01 COL IA ASS Q BY ENS, F A T A. EW OBK TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters lateut.

Patented Aug. 11, 1914.

Application filed July 14, 1806. Serial No. 326,252.

To all whom it may concern Be it known that I, EDWARD E. CLEMENT, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain'new and useful Improvements in Telephone-Exchange Systerns, of which the following is a specification, reference being .had'therein to the accompanying drawing.

My invention relates to telephone exchange systems and has for its object the improvement of such systems in the manner which will be hereinafter pointed out.

The characteristic features of my invention are: 1) manually controlled connecting means for answering the calls of subscribers in'an exchange; (2) automatic switching apparatus consisting of all relays arranged in decimal relation and adapted to connect the .manually connecting circuits with the wanted line; (3) step by step controlling means for the automatic switching apparatus; and

(4) manually cont-rolled keys or switches for workin the controlling apparatus.v

Brie y outlined, the present system comprises standard common battery line circuits terminating in jacks at the central otiice, each jack having its associated lamp and being adapted to receive the ordinary answering plug inserted by operators in the usual manner. Each answering plug is connected by a trunk line to a decimal set of relays, which for the sake of simplicity I shall illustrate and describe as containing line terminals but which may also and obviously contain the terminals of other trunks for working in large systems. These relays are controlled by step by step means which themselves are actuated by an operator through keys preferably associated with the trunks. The step by step means may be either step by step switches of the ordinary and well known type, having a circular series of contacts swept over by the arm or arms moved around step by step by a magnet, or they may be step by step interloc ing relays, these relays being in a double set of ten for the decimal relation, those of each set preparing those of the other alternately for operation as the successive impulses come over their controllin circuits.

In making a connection in this system, the operator plugs in in response to the subscribers call, takes the number in the usual way by meansof the listening key, and then supervisory lamp L.

proceeds to manipulate her keys or impulse sender so as to set up the step by step device to the number wanted. This then closes the circuits of the appropriate tens and units relays or" the decimal set, and by the energization thereof the plug circuit is immediately connected to the desired circuit selected. In the case of systems from 100 to 10,( )0O lines or more, the operation is necessar ly repeated as many times 'as there are (121g ts 1n the number wanted, each repetition e ecting one stepping operation and the set of one group of decimal relays, whereby the calling line is switched to the thousands trunk wanted, and then through that and by means of its decimal relays to the hundreds group and then through that and by means of the next set of decimal relays to the line wanted.

While I have described the step by step relays herein, any skilled engineer should be able to substitute step by step switches, such switches being known and their operation well understood.

My invention is illustrated in the accompanying drawings wherein- Figure 1 shows a subscribers station, the line wires of which terminate in central office apparatus. Fig. 2 shows the operators connective apparatus with a set of step by step selective relays. Fig. 3 shows a set of connector relays which are controlled by the step by step relays in Fig. 2.

Referring now to Fig. 1, the subscribers apparatus consists of the usual transmitter, receiver, ringers, condenser, and switchbook. The line wires 1 and 2 from this station terminate in a line relay M through the normally closed contacts of the cut-ofi' relay M. When this relay M is energized the circuit of the line lamp L is closed. 'W'h'en the circuit of the cut-off relay M is closed, the line relay is disconnected and the line Wires are connected to the springs j and j of the jack J. Referring now to Fig. 2, the answering end of the operators cord circuitterminates in the tip and sleeve 72 of the plug P. The answering end and calling end are separated by the condensers C and C. The two relays D and D are bridged across the answering) end and furnish battery to the calling su scriber as wellas controlling the The two relays, E and E are bridged across the calling end of the trunk and supply talking current to the called subscriber, as well as controlling the supervisorylamp L. The operator is provided with a sending device which I have represented diagrammatically by the two push buttons X and X. 'The spring. w of the button X is connected to therelay E, while the spring a: is connected directly to batter When this button is depressed, the relay is operated as one terminal is connected to ground. The operation of this relay closes the circuit of the relay F which supplies battery to the contact 6 of the relay E. The making and breaking of the contacts, e, e and e operate the relays of the set V in step by step order. The operatordepressing the button X the first time energizes the relay E but while the button is held down, none of the. relays in the set W are affected, but whenlthe button is released, the circuit of the relay H is closed through the contact e and e as battery has been placed on the contact e by the energizing of the locking relay F. V The operating of the relay H closes the circuit of the relay Wthrough the contacts h and h. Now, when the operator depresses the button, X the second time and the relay E is in an energizedcondition, the circuit of the relay W is closed through'the contacts 6 and a. When the pressure is again removed from the button, the circuit of the relay H is closed through the contacts w and 'w of the relay W. This operation can be kept upindefinitely, for every time the button X is operated, two relays of the set W are worked. Th relays H in the lower row are simply the guard relays and are operated when the relay E is deenergized and place the relays W and W, etc, in position to be operated when the relay E is energized.

Taking Figs. 2 and 3 to ether, the relay W when energized closes t e circuit of the first tens relay T. The rela WV when energized closes the .circuit 0 the relay T while. the relays V W and W control the relays T T and T The relays T and T etc.,'in the upper row are tens relays and each contains the multiples of ten lines and for a 100 line system there would be ten of these relays. The drawing only shows five of these relays and each relay containing the multiples of only five lines. I have shown the relays in this manner for simplicity as additional wiring would be confusing. The

lower set of relays T and TF etc, are the units relays and each contains multiples of the contacts o't'the upper set or tens relays. The relay T being the first units relay, contains the multiples of the first pair of cont-acts in each of the relays T, T etc, while the relay T contains the multiples of the second pair of contacts of these relays. The trunk wires-7 and 8 are multipled to contacts in the lower set or units relays. If the first tens relay T and the first units relay T are energized, the trunk' wires 7 and 8 will be connected to line 11 through the contacts t and t, and if the third relay T and the second units relay T were energized, the trunk wires would .be connected to line No. 32 through the contacts'zf and The tens relays are the first set of relays to be operated by the relay set W and are provided with two 'windings, an actuating windin which is controlled by the relay set ,Vi and a locking winding which is controlled by the relay F. The locking winding from each relay is connected to the common wirel6 leading to the contact f in the relay F, while the actuating windings are connected to the common wire 15 leading to ground through the contacts and f of the'relay F. Individual actuating wires 23, 24,25, 26 and 27 lead to the normally open contacts of the relays W, NV, etc. The units relays have only a single winding and are the second set of relays to be 0 erated by the relay set W Thewinding rom the first units relay T is connected in multiple with the actuating battery is placed on the wire 23 by the relay W, the relay T will be operated, being connected to ground through contacts of the relay F, but the relay T will not be affected as the common wire 14 is disconnected from ground. The relay F is in reality the switchingrelay and is operated after the first set of impulses, by the operator depressing the button X which connects ground to the relay E, whichin turn closesthe circuit of the relay F which remains locked through the contacts f and f and under control of the relay D. The operation. of the relay F removes ground from the common wire 15 of the tens set of relays and connects ground to the common wire 14. of the units set of relays. This relay also by closing the contacts f and f places bat.-

tery on the locking wire 16 which thereupon keeps the relay whichwas last operated :in an energized condition. When the button X. is depressed, operating the relay E, the

tery from the common wire 13 leading to the locking contacts of the relays in the set W. The relays of the set W are now restored to their normal position and are ready to be operated a second time by the button X. Insteadof operating or controlling the tens relays, they now control the uni-ts relays as the circuit ha'sbeen switched in the relay F." The operation of the relays the second time is the same as that already described, the only difference being that after the second set of impulses has been sent, the relays are not released as the" end of the trunk and opens the answering end of the trunk to prevent the calling subscriber receiving generator current back over his, line. At the end of the conversation when the operator withdraws the plug P, all the relays become deenergized and the apparatus is restored to its normal position.

The operation of'my system'is as follows:

The subscriber at station A removing his receiver closes the circuit ofthe line relay M which in turn closes the'circuit of the line lamp L, notifying the operator of a call. The operator receiving the signal, inserts the plug P into the jack J, energizing the relays Mf and D, the relay D being connected to battery While the relay M is connectcd to ground. The energizing of the relay M disconnects the line relay M and connects the line wires 1 and 2 through the extensions 3 and 4' to the springs j and 'jof the jack J. Upon asking the number and receiving the same 'she immediately depresses the button X a number of times .corresponding to the number asked for. Suppose the number asked for was 32. She will,

Y therefore, depress t-he'button X four times.

When. the button is first depressed, the relay E is energized and closes the circuit of the relay F by the following path: battery B. 21, 2-0, 6 e, 22, 'F to ground. The op-" eration of this relay placesbattery on the contacts e by thefollowing path: battery B, 21, 20, c, e, 28, f f 13, to e. The relay F also places battery on the extension wire 13 which is common to all the locking contacts of the relays in the set W; Battery is now placed on the wire 18 through the contacts e and e, but the contacts 11 and 'h' of the relay H are open at this juncture and the relay lV is not affected. After the first impulse the relay E becoming deenergized,

' closes the contacts e and c placing battery on the wire 19 through the contacts w and w to the relay H and ground. The relay- Hthereupon becomes energized and locks itself through the contactsh and It leading to the locking wire 13. The contacts h and h are also closed thus connecting the wire 18 to the relayWV through the'contacts' h and [L of the relay H. The operator now depresses the button X the second time, en-

ergizing the relay E which in'turn closes the circuit of the relay ll 'by thepath'already traced. After the second iinpulse' the contacts Zr and 6 being closed'the circuit of the relay H *is completed'through the contacts to" and 10 of the relay 7'. The operator depressing the button' the first time does not operate any of the Selectiyerelays W, etc, but simply closes the circuit of the relay H placing the set W, Vi, etc

in'conclition to be'ioperated. So of course it follows that'the first impulse is only a preliminary start as it doeslnot operate any of the relays in Fig. 3, and instead of depressing the button three times she h'as'tod'epress' it four times to operate thethird relay. -The operator [depressing the button the third time first closes the circuit of the relay W- through the contact hand h of the relay H and second the relay H through the contact w and w of the relay W. The fourth time thebutton is depressed thefrelay W and H are operated. When the'relay W" was operated at the second impulse the (ircuit of the first tens relay T was closed by the following path: battery B, 21,40 a, 29 ill) zl 22 13, ll, 4,6, 5 23: 15, 1, f f, to ground. This relay'T does not remain locked as the common locking wire 16 is open in the relay F. At the third impulse the operation of the relay \W' closes the c ire-uit of the relay T over the wire 24 and at the same time opens the circuit'of the relay T by breaking the contacts a and w. At the fourth impulse the relay W operating, closes the circuit of the relay T and at the same time ,opens the circuit of the relay T by breaking'the contacts 10 and w As the relay T contains the contacts leading to the desired line the operator depresses the button, X and then proceeds to select No. 2 units relay. The operating,

of the button X" closes the circuit of the relay E which in turn closes the circuit of: 'the switching relay F. In the relay E" the opening of the contacts a and e" and e and e, disconnects the relay F and releases all of the relays in the set V. The operatin; of the relay F connects battery to the wire 16 which maintains the circuitof the relay T which is encrgiied at this time. The relay T is the only one of the set that can be affected by battery being placed on wire 16 as its locking circuit is connected to ground through its contacts't and t -Ground is now removed from thecommon Wire 15 of the tens relays'by the opening of the contacts f and y. and ground is connected to the common wire 14of'tl1eunits relays. The relay set W is now again in position to be operated by the second set of impulses, the only difference being that the units relays are now controlled in place of the tens relays. The operator sends in three impulses to select the second units relay T clays in the set \V are operated in the same-manner as before and when the relay \V -isselected, the circuit ,of the relay T is closed through the wire 24. The calling subscriber is now connected to the called subscriber through't-he cordcircuit and contacts of the tens-and units relays, and the operator depressing the buttons X and X, places generator current on the called line. By means of the supervisory lamp L she is enabled to tell when the called party answers his telephone. At the end of the conversation when both parties hang up,- the supervisory lamps L and L glow, notifying the operator of the fact who at once withdraws 1 the plug P from the jack J. The withdrawing of the plug removes battery from the wires Sland ll, deenergizing the relays F and F thereby releasing relays in the set W and the tens and .units relays in Fig. 3, thus restoring all apparatus to its normal or idle position. I 1

Having thus described my invention, what I claim and desire to secure by Letters Pat- 1. In a telephone exchange system, a plurality of' lines and means to selectively connect therewith comprising a series of relays arranged in numerical order corresponding to the digits to be selected and adapted to be energized successively by current impulses, the energization of each succeeding relay being dependent upon the energization aof those recedin it. 40 P g 2. In a telephone exchange system, means for selecting want-ed lines comprising a serics of relays brought into association with a calling line; for that purpose, local controlling circuits for said relays less in numher than the number of relays, and means for sending current impulses over said controlling circuits to energize the selective relays in step by step succession.

- 3. In a telephone exchange system, a pinrality of talking circuits, and means for selectively interconnect-ing the same composed of contact devices and controlling means thereof comprising a series of relays adapt-- ed to be operated step by step in succession, the circuit of each succeeding'relay being partly cont-rolled by those preceding it, whereby the number wanted is reached by building up the controlling circuit.

4. In a telephone exchange system, connecting ueans and selective controlling means therefor consisting of a double set of interlocking relays, a double controlling circuit, and means to apply current impulses to the two sides of the circuit alternately, whereby the relays may be operated step by step in sequence and may thereby be caused to select any desired circuit.

5. In a telephone exchange system, a plurality of line circuits to be'interconnected, means associated with said lines for indicating a call, manually operated connective means for answering a call and extending the line calling to the switching apparatus, a group or groups of relays constituting said switching apparatus, and means for controlling the same, itself controlled over a portion of the talkin circuit.

6. In a telephone exciange system, a plurality of, line circuits, means associated with each line for indicating a call, means for extending the line in response to thecall to automatic switching apparatus, connecting relays constituting said switching apparatus,.and controlling relays for the connecting relays.

I. In a telephone exchange system, line connecting means comprising a double digit system of relays determining the connection of a calling trunk with a desired line, and a series of interlocking relays responding to step by step impulses and controlling the double digit relays.

, 8. In a telephone exchange system, a plua. teletion, and an answering jack with an associated calling signal at the central office, answering plugs adapted to cobperate .with said answering jacks, an automatic connector switching apparatus connected by a trunk circuit to each plug, selective actuating meansfor said switching apparatus directly connected thereto when set, and man- 'lay means separately operated to preset the actuating means.

9. In a telephone exchange system, a plurality of line circuits, a plurality of connecting trunks-less in number thanthe num ber of line circuits, with means to connect an idle'trunk to a calling line, automatic switching apparatus forming the terminal of each trunk, selective actuating means for the switching apparatus also associated with the trunk and exclusively controlling the actuation of the switching apparatus, which actuating means is operated in advance of the operation of the switching apparatus, and separate and additional manually operative means for so operating said actuating means.

10. In a telephone exchange system. a plurality of line circuits, a number of connecting trunks less than the number of lines, means for connecting an idle trunk to a calling line, an automatic switching apparatus forming the calling terminal of each trunk and adapted when actuated to select any desired line circuit and connect the trunk therewith, actuating means for' said switching'apparatus composed of Clements circuits, a group of connecting relays associated with each trunk and adapted to connect the same selectivel to any one of the other circuits, a step y step controlling switching deviceadapted to select and connect said relays in proper order to complete any desired connection, and manually operatcd means for actuating said step by step device.

12. In a telephone exchange system, a plurality of line circuits and a plurality of trunks less in number than the number of linecircuits, with means to connect an idle trunk with a calling line, automatic switching apparatusv connected to 5nd constituting the calling terminal for each trunk, a set of controlling relays adapted when set to selectively actuate said switching apparatus, and manually o erated means for antecedently setting sai relays for the selection of any desired number by the switching apparatus.

' 13. In a telephone system, two associated sets of selective relays, controlling wires common thereto, an actuating wire indi vidual to each set, divided into sections controlled by contacts of relays in the other set, and means to build up said actuating wires to energize any desired relay of either set by sendmg impulses through the two actuat- I ing wires in succession.

14. In a telephone system, a double set ,of selecting relays containing banks of line contacts, a set of controlling relays whose armatures control the energization of the selecting relays, and manual means for operating said controlling relays so as to 0perate the proper combination of selecting relays for closing any desired line circuits.

15. In a telephone exchange system, a

any desired digit by a single direct applrv cation of current, and pre-setting means for the actuating means adapted to selectively operate the same in successive steps.

16. A selecting device for a telephone or signaling system comprising two sets of relays, one set controlling operating wires, the second set controlling the connection of the individual relays of the first setto an actuating wire, and means whereby the relays of the first set may severally and respectively control the circuits of the corresponding relays of the second set, so that selective connection with the controlling wires can only be attained by associated action of predetermined relays in the two sets.

17. In a telephone exchange system, a plurality of line circuits to be interconnected, a plurality of manual connective terminals less in number than the number of line circuits, and a plurality of relays for each connective terminal, in decimal re-- lation with each other, adapted when actuated to automatically connect a line circuit with a connective terminal.

18. In a telephone exchange system, subscribers lines, connective links therefor provided with automatic connective apparatus comprising digital sets of connecting relays and impulse actuated governing means therefor, an impulse sending device, a signaling device and a common battery at the central station arranged to supply talking current for the subscribers lines, and ener gizmg current for the impulse sendlng device and the automatic connective appacopics ot this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). G. 

